Fix z-index back

Author: aversey

docs/css/custom.css

@@ -169,6 +169,27 @@
   content: "Switch to the light theme to view the diagram.";
 }
 
+/*******************************************************/
+/* Fix z-index. */
+header.md-header {
+  z-index: 900 !important;
+}
+.md-sidebar {
+  z-index: 1000 !important;
+}
+.md-overlay {
+  z-index: 950 !important;
+}
+.md-search__overlay {
+  z-index: 1100 !important;
+}
+.md-search__form {
+  z-index: 1200 !important;
+}
+.md-search__output {
+  z-index: 1100 !important;
+}
+
 /*******************************************************/
 /* Hide repo stats. */
 .md-source__fact--stars, .md-source__fact--forks {